Determination of geometric features of objects, for example of manufactured objects such as automotive metal parts, plastic parts and so on, or of natural objects, can be of great value in industry and elsewhere. Geometric features of manufactured objects that may be of interest may include the size, location and shape of edges, including bores, external edges and the like, for example. Often, such edges may conform to non-standard shapes, and are thus not subject to identification and/or classification by prior art methods.
By way of general background interest, U.S. Pat. No. 6,212,481 discloses an automatically shape calculating method and apparatus for contour shape measuring machines, by which a geometric shape value and a geometric shape boundary value are calculated from shape data. A geometric shape boundary is provisionally set in accordance with the shape data, which is obtained by measuring a workpiece, and then geometric shape calculation areas are set in areas except for the vicinities of the provisionally set point, a measurement starting point and a measurement ending point. A geometric shape value of the shape data is calculated while a geometric shape of the shape data is determined under geometric shape recognition conditions for each of the set geometric shape calculation areas. The geometric shape boundary value is calculated from the calculated geometric shape value, and the calculating results are output.
Also by way of general background interest, U.S. Pat. No. 5,434,803 discloses a coordinate measuring machine and the method of measuring therein wherein the instruction of the geometric shape is prevented from mistaking and the geometric shape of the workpiece is measured without interrupting the joystick operation. The measuring direction of the probe and the measured value of workpiece are taken in the data receiving part. The geometric shape calculation part calculates the errors of each geometric shape based on the measured value from the data receiving part and the formula which was input previously and represents the geometric shape such as “a straight line or circle”.